摘要
In this paper, the Minolta CM-2002 spectrophotometer was used to measure the color reflectance data of sediments in Core MZ11,which was taken from the Yangtze River mud area. The authors found the brightness could be a good proxy to monitor paleoclimatic changes in the study area and a time series analysis of the factor F1 and brightness indicate that relative high values in the past 100 yr occurred in 1 887 a,1 897a,1 904 a,1 915 a,1 936 a,1 945 a,1 953 a,1 965 a,1 977 a,1 987 a and 1992a,which may correlate with the abnormally strong summer monsoon events,suggesting that the tropical ocean had a major effect on the East Asian summer monsoon.Periodicities of 28 year and 2 year are observed in the color reflectance records coinciding with those known for solar cycles in the past 100 year might be resulted from changes in solar activity.